Wir möchten Morgenröte Edmonds für eine kritische Lektüre des Manuskripts danken. Die Stagljar Labor wird aus Mitteln der kanadischen Stiftung für Innovation (CFI), die Canadian Institute for Health Research (CIHR), der Heart and Stroke Foundation, die Canadian Cancer Society und Novartis unterstützt.

<ol>
	<li>Stagljar, I., Fields, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+membrane+protein+interactions+using+yeast-based+technologies.">Analysis of membrane protein interactions using yeast-based technologies.</a> Trends Biochem Sci. 27 (11), 559-563 (2002).</li><li>Iyer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Utilizing+the+split-ubiquitin+membrane+yeast+two-hybrid+system+to+identify+protein-protein+interactions+of+integral+membrane+proteins.">Utilizing the split-ubiquitin membrane yeast two-hybrid system to identify protein-protein interactions of integral membrane proteins.</a> Sci STKE. 275, pl3-pl3 (2005).</li><li>Paumi, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+protein-protein+interactions+for+the+yeast+ABC+transporter+Ycf1p+by+integrated+split-ubiquitin+membrane+yeast+two-hybrid+analysis.">Mapping protein-protein interactions for the yeast ABC transporter Ycf1p by integrated split-ubiquitin membrane yeast two-hybrid analysis.</a> Mol Cell. 26 (1), 15-25 (2007).</li><li>Stagljar, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+genetic+system+based+on+split-ubiquitin+for+the+analysis+of+interactions+between+membrane+proteins+in+vivo.">A genetic system based on split-ubiquitin for the analysis of interactions between membrane proteins in vivo.</a> Proc Natl Acad Sci U S A. 95 (9), 5187-5192 (1998).</li><li>Gisler, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+protein-protein+interactions+between+the+mammalian+integral+membrane+transporters+and+PDZ-interacting+partners+using+a+modified+split-ubiquitin+membrane+yeast+two-hybrid+system.">Monitoring protein-protein interactions between the mammalian integral membrane transporters and PDZ-interacting partners using a modified split-ubiquitin membrane yeast two-hybrid system.</a> Mol Cell Proteomics. 7 (7), 1362-1377 (2008).</li><li>Scheper, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coordination+of+N-glycosylation+and+protein+translocation+across+the+endoplasmic+reticulum+membrane+by+Sss1+protein.">Coordination of N-glycosylation and protein translocation across the endoplasmic reticulum membrane by Sss1 protein.</a> J Biol Chem. 278 (39), 37998-38003 (2003).</li><li>Thaminy, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+novel+ErbB3-interacting+factors+using+the+split-ubiquitin+membrane+yeast+two-hybrid+system.">Identification of novel ErbB3-interacting factors using the split-ubiquitin membrane yeast two-hybrid system.</a> Genome Res. 13 (7), 1744-1753 (2003).</li><li>Johnsson, N., Varshavsky, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Split+ubiquitin+as+a+sensor+of+protein+interactions+in+vivo.">Split ubiquitin as a sensor of protein interactions in vivo.</a> Proc Natl Acad Sci U S A. 91 (22), 10340-10344 (1994).</li><li>Kelleher, D. J., Gilmore, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Saccharomyces+cerevisiae+oligosaccharyltransferase+is+a+protein+complex+composed+of+Wbp1p,+Swp1p,+and+four+additional+polypeptides.">The Saccharomyces cerevisiae oligosaccharyltransferase is a protein complex composed of Wbp1p, Swp1p, and four additional polypeptides.</a> J Biol Chem. 269 (17), 12908-12917 (1994).</li><li>Chevallier, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cloning+and+transcriptional+control+of+a+eucaryotic+permease+gene.">Cloning and transcriptional control of a eucaryotic permease gene.</a> Mol Cell Biol. 2 (8), 977-984 (1982).</li></ol>

Igor Stagljar ist ein Mitbegründer der Dualsystems Biotech, Schweiz.

MYTHOS ist das erste System mit hohem Durchsatz, die die Identifizierung von Wechselwirkungen zwischen full-length Membranproteinen und cytosolische oder membrangebundene Partnern ermöglicht. Es wurde verwendet, um Membranprotein aus einer Reihe von Organismen [3-7] zu studieren. Es gibt jedoch bestimmte Details, die müssen unter die Lupe, um sicherzustellen, das Protein-of-interest zugänglich ist mit MYTHOS Studie werden können. Viele membrangebundene Proteine ​​sind an die Plasmame...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Polyethenlene Glycol (PEG3350)</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>PEG335</td>
<td>&nbsp;</td>
<tr>
<td>Lithium Acetate Bihydrate</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>LIA001</td>
<td>&nbsp;</td>
<tr>
<td>X-Gal (5-Bromo-4-Chloro-3-Indolyl-b-D-galactopyranoside)</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>XGA001</td>
<td>&nbsp;</td>
<tr>
<td>N`,N-dimethyl formamide</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>DMF 451</td>
<td>&nbsp;</td>
<tr>
<td>3-amino-1,2,4-triazole (3-AT)</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>ATT124</td>
<td>&nbsp;</td>
<tr>
<td>Sodium phosphate dibasic</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>SPD307</td>
<td>&nbsp;</td>
<tr>
<td>Sodium phosphate monobasic</td>
<td>&nbsp;</td>
<td>FisherBiotech</td>
<td>BP329-500</td>
<td>&nbsp;</td>
<tr>
<td>Salmon Sperm DNA</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>CA80601-120</td>
<td>&nbsp;</td>
<tr>
<td>D-Glucose</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>GLU501</td>
<td>&nbsp;</td>
<tr>
<td>LB Broth LENOX</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>LBL405</td>
<td>&nbsp;</td>
<tr>
<td>Yeast Nitrogen Base</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>YNB406</td>
<td>&nbsp;</td>
<tr>
<td>Yeast Extract</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>YEX401</td>
<td>&nbsp;</td>
<tr>
<td>Peptone</td>
<td>&nbsp;</td>
<td>Beckton Dickinson</td>
<td>211677</td>
<td>&nbsp;</td>
<tr>
<td>Bio-Tryptone</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>TRP402</td>
<td>&nbsp;</td>
<tr>
<td>Adenine Sulphate</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>ADS201</td>
<td>&nbsp;</td>
<tr>
<td>L-Uracil</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>URA241</td>
<td>&nbsp;</td>
<tr>
<td>L-Threonine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>THR002</td>
<td>&nbsp;</td>
<tr>
<td>L-Histidine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>HIS200</td>
<td>&nbsp;</td>
<tr>
<td>L-Methionine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>MET222</td>
<td>&nbsp;</td>
<tr>
<td>L-Valine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>VAL201</td>
<td>&nbsp;</td>
<tr>
<td>L-Phenylalanine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>PHA302</td>
<td>&nbsp;</td>
<tr>
<td>L-Isoleucine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>ISO910</td>
<td>&nbsp;</td>
<tr>
<td>L-Tyrosine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>TYR333</td>
<td>&nbsp;</td>
<tr>
<td>L-Leucine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>LEU222</td>
<td>&nbsp;</td>
<tr>
<td>L-Arginine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>ARG006</td>
<td>&nbsp;</td>
<tr>
<td>L-Tryptophane</td>
<td>&nbsp;</td>
<td>FisherBiotech</td>
<td>BP395-100</td>
<td>&nbsp;</td>
<tr>
<td>L-Lysine</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>LYS101</td>
<td>&nbsp;</td>
<tr>
<td>L-Alanine</td>
<td>&nbsp;</td>
<td>FisherBiotech</td>
<td>BP369-100</td>
<td>&nbsp;</td>
<tr>
<td>Agar</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>AGR001</td>
<td>&nbsp;</td>
<tr>
<td>Soda Lime Galss Beads</td>
<td>&nbsp;</td>
<td>BioSpec Product</td>
<td>11079105</td>
<td>&nbsp;</td>
<tr>
<td>Sodium Chloride</td>
<td>&nbsp;</td>
<td>Bioshop</td>
<td>SLD002</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

split-ubiquitin based membrane yeast two-hybrid (myth) system: a powerful tool for identifying protein-protein interactions

Die grundlegenden biologischen und klinischen Bedeutung von integralen Membranproteinen veranlasste die Entwicklung einer Hefe-basiertes System für die Hochdurchsatz-Identifizierung von Protein-Protein-Interaktionen (PPI) für full-length Transmembranproteine. Zu diesem Zweck entwickelt unser Labor das Split-Ubiquitin-basierten Membrane Yeast Two-Hybrid (Mythos) System. Diese Technologie ermöglicht den empfindlichen Nachweis von transienten und stabilen Protein-Wechselwirkungen mit<em&gt; Saccharomyces cerevisiae</em&gt; Als Wirtsorganismus. MYTHOS nutzt die Beobachtung, dass Ubiquitin in zwei stabile Einheiten getrennt werden können: Die C-terminale Hälfte von Hefe-Ubiquitin (C<sub&gt; Ub</sub&gt;) Und die N-terminale Hälfte des Ubiquitin-Einheit (N<sub&gt; Ub</sub&gt;). Im Mythos wird dieser Grundsatz für den Einsatz als &quot;Sensor&quot; von Protein-Protein-Wechselwirkungen angepasst. Kurz gesagt, ist die integrale Membranproteine ​​Köderprotein zu C verschmolzen<sub&gt; Ub</sub&gt; Was ist es, eine künstliche Transkriptionsfaktor gebunden. Prey Proteine, entweder in einzelnen oder Bibliothek-Format werden die N verschmolzen<sub&gt; Ub</sub&gt; Einheit. Protein-Interaktion zwischen den Köder und Beute führt zum Auflösen des Ubiquitin-Einheiten bilden eine full-length &quot;pseudo-Ubiquitin-Molekül. Dieses Molekül wiederum ist durch cytosolische deubiquitinating Enzyme erkannt, was zur Spaltung des Transkriptionsfaktors, und die anschließende Induktion der Expression des Reportergens. Das System ist sehr anpassungsfähig und eignet sich besonders für High-Throughput-Screening geeignet. Es wurde erfolgreich eingesetzt, um Interaktionen mit integralen Membranproteinen aus Hefe-und anderen Organismen zu untersuchen.

Watch this Scientific Journal Video about Split-Ubiquitin Based Membrane Yeast Two-Hybrid MYTH System: A Powerful Tool For Identifying Protein-Protein Interactions at JoVE.com

Split-Ubiquitin Based Membrane Yeast Two-Hybrid MYTH System: A Powerful Tool For Identifying Protein-Protein Interactions

MYTHOS ermöglicht den empfindlichen Nachweis von transienten und stabilen Wechselwirkungen zwischen Proteinen, die im Modellorganismus Saccharomyces cerevisiae exprimiert werden. Es wurde erfolgreich angewendet, um exogene und Hefe integrale Membranproteine ​​zu studieren, um ihre Interaktionspartner in einem hohen Durchsatz Weise zu identifizieren.

Split-Ubiquitin Basierend Membrane Yeast Two-Hybrid (Mythos) System: Ein wirksames Instrument zur Ermittlung von Protein-Protein-Wechselwirkungen

The fundamental biological and clinical importance of integral membrane proteins prompted the development of a yeast-based system for the high-throughput ...

split-ubiquitin-based-membrane-yeast-two-hybrid-myth-system-powerful

Research

JoVE Journal

Biology

Split-Ubiquitin Based Membrane Yeast Two-Hybrid (MYTH) System: A Powerful Tool For Identifying Protein-Protein Interactions

30.9K Aufrufe.  University of Toronto. MYTHOS ermöglicht den empfindlichen Nachweis von transienten und stabilen Wechselwirkungen zwischen Proteinen, die im Modellorganismus Saccharomyces cerevisiae exprimiert werden. Es wurde erfolgreich angewendet, um exogene und Hefe integrale Membranproteine ​​zu studieren, um ihre Interaktionspartner in einem hohen Durchsatz Weise zu identifizieren.

Serie: Split-Ubiquitin Based Membrane Yeast Two-Hybrid MYTH System: A Powerful Tool For Identifying Protein-Protein Interactions

Imaging Protein-protein Interactions in vivo

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, preventing their identification and analysis through traditional biochemical methods such as co-immunoprecipitation. In this regard, the genetically encodable fluorescent proteins (GFP, RFP, etc.) and their associated overlapping fluorescence spectrum have revolutionized our ability to monitor weak interactions in vivo using F&ouml;rster resonance energy transfer (FRET)1-3. Here, we detail our use of a FRET-based proximity assay for monitoring receptor-receptor interactions on the endothelial cell surface.

Imaging Protein-protein Interactions in vivo

This protocol describes how to image protein-protein interactions using a FRET-based proximity assay.

Imaging Protein-Protein-Wechselwirkungen In vivo</em

Protein-protein interactions are a hallmark of all essential cellular processes. However, many of these interactions are transient, or energetically weak, ...

Forschung

Biologie

Associated Chromosome Trap for Identifying Long-range DNA Interactions

Genetic information encoded by DNA is organized in a complex and highly regulated chromatin structure. Each chromosome occupies a specific territory, that may change according to stage of development or cell cycle. Gene expression can occur in specialized transcriptional factories where chromatin segments may loop out from various chromosome territories, leading to co-localization of DNA segments which may exist on different chromosomes or far apart on the same chromosome. The Associated Chromosome Trap (ACT) assay provides an effective methodology to identify these long-range DNA associations in an unbiased fashion by extending and modifying the chromosome conformation capture technique. The ACT assay makes it possible for us to investigate mechanisms of transcriptional regulation in trans, and can help explain the relationship of nuclear architecture to gene expression in normal physiology and during disease states.

The associated chromosome trap (ACT) assay is a novel unbiased method for identifying long-range DNA interactions. The characterization of long range DNA interactions will allow us to determine the relationship of nuclear architecture to gene expression in both normal physiology and in diseased states.

Assoziierte Chromosome-Trap zur Identifizierung weiträumige DNA-Wechselwirkungen

Genetic information encoded by DNA is organized in a complex and highly regulated chromatin structure.  Each chromosome occupies a specific territory, ...

Modified Yeast-Two-Hybrid System to Identify Proteins Interacting with the Growth Factor Progranulin

Progranulin (PGRN), also known as granulin epithelin precursor (GEP), is a 593-amino-acid autocrine growth factor. PGRN is known to play a critical role in a variety of physiologic and disease processes, including early embryogenesis, wound healing 1, inflammation 2, 3, and host defense 4. PGRN also functions as a neurotrophic factor 5, and mutations in the PGRN gene resulting in partial loss of the PGRN protein cause frontotemporal dementia 6, 7. Our recent studies have led to the isolation of PGRN as an important regulator of cartilage development and degradation 8-11. Although PGRN, discovered nearly two decades ago, plays crucial roles in multiple physiological and pathological conditions, efforts to exploit the actions of PGRN and understand the mechanisms involved have been significantly hampered by our inability to identify its binding receptor(s). To address this issue, we developed a modified yeast two-hybrid (MY2H) approach based on the most commonly used GAL4 based 2-hybrid system. Compared with the conventional yeast two-hybrid screen, MY2H dramatically shortens the screen process and reduces the number of false positive clones. In addition, this approach is reproducible and reliable, and we have successfully employed this system in isolating the binding proteins of various baits, including ion channel 12, extracellular matrix protein 10, 13, and growth factor14. In this paper, we describe this MY2H experimental procedure in detail using PGRN as an example that led to the identification of TNFR2 as the first known PGRN-associated receptor 14, 15.

We have modified the conventional yeast two-hybrid screening, an effective genetic tool in identifying protein interaction. This modification markedly shortens the process, reduces the workload, and most importantly, reduces the number of false positives. In addition, this approach is reproducible and reliable.

Modifizierten Hefe-Zwei-Hybrid-System, um Proteine ​​interagieren mit dem Growth Factor Progranulin Identifizieren

Progranulin (PGRN), also known as granulin epithelin precursor (GEP), is a 593-amino-acid autocrine growth factor. PGRN is known to play a critical role ...

A Protocol for the Identification of Protein-protein Interactions Based on 15N Metabolic Labeling, Immunoprecipitation, Quantitative Mass Spectrometry and Affinity Modulation

Protein-protein interactions are fundamental for many biological processes in the cell. Therefore, their characterization plays an important role in current research and a plethora of methods for their investigation is available1. Protein-protein interactions often are highly dynamic and may depend on subcellular localization, post-translational modifications and the local protein environment2. Therefore, they should be investigated in their natural environment, for which co-immunoprecipitation approaches are the method of choice3. Co-precipitated interaction partners are identified either by immunoblotting in a targeted approach, or by mass spectrometry (LC-MS/MS) in an untargeted way. The latter strategy often is adversely affected by a large number of false positive discoveries, mainly derived from the high sensitivity of modern mass spectrometers that confidently detect traces of unspecifically precipitating proteins. A recent approach to overcome this problem is based on the idea that reduced amounts of specific interaction partners will co-precipitate with a given target protein whose cellular concentration is reduced by RNAi, while the amounts of unspecifically precipitating proteins should be unaffected. This approach, termed QUICK for QUantitative Immunoprecipitation Combined with Knockdown4, employs Stable Isotope Labeling of Amino acids in Cell culture (SILAC)5 and MS to quantify the amounts of proteins immunoprecipitated from wild-type and knock-down strains. Proteins found in a 1:1 ratio can be considered as contaminants, those enriched in precipitates from the wild type as specific interaction partners of the target protein. Although innovative, QUICK bears some limitations: first, SILAC is cost-intensive and limited to organisms that ideally are auxotrophic for arginine and/or lysine. Moreover, when heavy arginine is fed, arginine-to-proline interconversion results in additional mass shifts for each proline in a peptide and slightly dilutes heavy with light arginine, which makes quantification more tedious and less accurate5,6. Second, QUICK requires that antibodies are titrated such that they do not become saturated with target protein in extracts from knock-down mutants.
Here we introduce a modified QUICK protocol which overcomes the abovementioned limitations of QUICK by replacing SILAC for 15N metabolic labeling and by replacing RNAi-mediated knock-down for affinity modulation of protein-protein interactions. We demonstrate the applicability of this protocol using the unicellular green alga Chlamydomonas reinhardtii as model organism and the chloroplast HSP70B chaperone as target protein7 (Figure 1). HSP70s are known to interact with specific co-chaperones and substrates only in the ADP state8. We exploit this property as a means to verify the specific interaction of HSP70B with its nucleotide exchange factor CGE19.

A Protocol for the Identification of Protein-protein Interactions Based on 15N Metabolic Labeling, Immunoprecipitation, Quantitative Mass Spectrometry and Affinity Modulation

We present a variation of the QUICK (QUantitative Immunoprecipitation Combined with Knockdown) approach that was introduced previously to distinguish between true and false protein-protein interactions. Our approach is based on 15N metabolic labeling, the modulation of affinities of protein-protein interactions by the presence/absence of ATP, immunoprecipitation, and quantitative mass spectrometry.

Ein Protokoll für die Identifizierung von Protein-Protein-Wechselwirkungen Basierend auf<sup&gt; 15</sup&gt; N Metabolische Markierung, Immunpräzipitation, Quantitative Massenspektrometrie und Affinity Modulation

Protein-protein interactions are fundamental for many biological processes in the cell. Therefore, their characterization plays an important role in ...

Identifying Protein-protein Interaction in Drosophila Adult Heads by Tandem Affinity Purification (TAP)

Genetic screens conducted using Drosophila melanogaster (fruit fly) have made numerous milestone discoveries in the advance of biological sciences. However, the use of biochemical screens aimed at extending the knowledge gained from genetic analysis was explored only recently. Here we describe a method to purify the protein complex that associates with any protein of interest from adult fly heads. This method takes advantage of the Drosophila GAL4/UAS system to express a bait protein fused with a Tandem Affinity Purification (TAP) tag in fly neurons in vivo, and then implements two rounds of purification using a TAP procedure similar to the one originally established in yeast1 to purify the interacting protein complex. At the end of this procedure, a mixture of multiple protein complexes is obtained whose molecular identities can be determined by mass spectrometry. Validation of the candidate proteins will benefit from the resource and ease of performing loss-of-function studies in flies. Similar approaches can be applied to other fly tissues. We believe that the combination of genetic manipulations and this proteomic approach in the fly model system holds tremendous potential for tackling fundamental problems in the field of neurobiology and beyond.

Identifying Protein-protein Interaction in Drosophila Adult Heads by Tandem Affinity Purification TAP

Drosophila is famous for its powerful genetic manipulation, but not for its suitability of in-depth biochemical analysis. Here we present a TAP-based procedure to identify interacting partners of any protein of interest from the fly brain. This procedure can potentially lead to new avenues of research.

Identifizierung von Protein-Protein-Wechselwirkung in<em&gt; Drosophila</em&gt; Adult Heads von Tandem Affinity Purification (TAP)

Genetic screens conducted using Drosophila melanogaster (fruit fly) have made numerous milestone discoveries in the advance of biological sciences. ...

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists

As a critical regulator of drug metabolism and inflammation, Pregnane X Receptor (PXR), plays an important role in disease pathophysiology linking metabolism and inflammation (e.g.&#160;hepatic steatosis)1,2. There has been much progress in the identification of agonist ligands for PXR, however, there are limited descriptions of drug-like antagonists and their binding sites on PXR3,4,5. A critical barrier has been the inability to efficiently purify full-length protein for structural studies with antagonists despite the fact that PXR was cloned and characterized in 1998. Our laboratory developed a novel high throughput yeast based two-hybrid assay to define an antagonist, ketoconazole&#39;s, binding residues on PXR6. Our method involves creating mutational libraries that would rescue the effect of single mutations on the AF-2 surface of PXR expected to interact with ketoconazole. Rescue or &#34;gain-of-function&#34; second mutations can be made such that conclusions regarding the genetic interaction of ketoconazole and the surface residue(s) on PXR are feasible. Thus, we developed a high throughput two-hybrid yeast screen of PXR mutants interacting with its coactivator, SRC-1. Using this approach, in which the yeast was modified to accommodate the study of the antifungal drug, ketoconazole, we could demonstrate specific mutations on PXR enriched in clones unable to bind to ketoconazole. By reverse logic, we conclude that the original residues are direct interaction residues with ketoconazole. This assay represents a novel, tractable genetic assay to screen for antagonist binding sites on nuclear receptor surfaces. This assay could be applied to any drug regardless of its cytotoxic potential to yeast as well as to cellular protein(s) that cannot be studied using standard structural biology or proteomic based methods. Potential pitfalls include interpretation of data (complementary methods useful), reliance on single Y2H method, expertise in handling yeast or performing yeast two-hybrid assays, and assay optimization.

Ketoconazole binds to and antagonizes Pregnane X Receptor (PXR) activation. Yeast high throughput screens of PXR mutants define a unique region for ketoconazole binding. This yeast-based genetic method discovers novel nuclear receptor interactions with ligands that associate with surface binding sites.

Reverse-Hefe-Zwei-Hybrid-System an Säugetier Nuclear Receptor Rückstände Identifizieren Sie, dass Interagieren Sie mit Liganden und / oder Antagonisten

As a critical regulator of drug metabolism and inflammation, Pregnane X Receptor (PXR), plays an important role in disease pathophysiology linking ...

Capture Compound Mass Spectrometry - A Powerful Tool to Identify Novel c-di-GMP Effector Proteins

Considerable progress has been made during the last decade towards the identification and characterization of enzymes involved in the synthesis (diguanylate cyclases) and degradation (phosphodiesterases) of the second messenger c-di-GMP. In contrast, little information is available regarding the molecular mechanisms and cellular components through which this signaling molecule regulates a diverse range of cellular processes. Most of the known effector proteins belong to the PilZ family or are degenerated diguanylate cyclases or phosphodiesterases that have given up on catalysis and have adopted effector function. Thus, to better define the cellular c-di-GMP network in a wide range of bacteria experimental methods are required to identify and validate novel effectors for which reliable in silico predictions fail.
We have recently developed a novel Capture Compound Mass Spectrometry (CCMS) based technology as a powerful tool to biochemically identify and characterize c-di-GMP binding proteins. This technique has previously been reported to be applicable to a wide range of organisms1. Here we give a detailed description of the protocol that we utilize to probe such signaling components. As an example, we use Pseudomonas aeruginosa, an opportunistic pathogen in which c-di-GMP plays a critical role in virulence and biofilm control. CCMS identified 74% (38/51) of the known or predicted components of the c-di-GMP network. This study explains the CCMS procedure in detail, and establishes it as a powerful and versatile tool to identify novel components involved in small molecule signaling.

The ubiquitous second messenger c-di-GMP controls growth and behavior of many bacteria. We have developed a novel Capture Compound Mass Spectrometry based technology to biochemically identify and characterize c-di-GMP binding proteins in virtually any bacterial species.

Capture Compound Mass Spectrometry - Ein leistungsfähiges Tool zum Identifizieren Novel c-di-GMP Effektorproteinen

Considerable progress has been made during the last decade towards the identification and characterization of enzymes involved in the synthesis ...

Investigating Protein-protein Interactions in Live Cells Using Bioluminescence Resonance Energy Transfer

Assays based on Bioluminescence Resonance Energy Transfer (BRET) provide a sensitive and reliable means to monitor protein-protein interactions in live cells. BRET is the non-radiative transfer of energy from a 'donor' luciferase enzyme to an 'acceptor' fluorescent protein. In the most common configuration of this assay, the donor is Renilla reniformis luciferase and the acceptor is Yellow Fluorescent Protein (YFP). Because the efficiency of energy transfer is strongly distance-dependent, observation of the BRET phenomenon requires that the donor and acceptor be in close proximity. To test for an interaction between two proteins of interest in cultured mammalian cells, one protein is expressed as a fusion with luciferase and the second as a fusion with YFP. An interaction between the two proteins of interest may bring the donor and acceptor sufficiently close for energy transfer to occur. Compared to other techniques for investigating protein-protein interactions, the BRET assay is sensitive, requires little hands-on time and few reagents, and is able to detect interactions which are weak, transient, or dependent on the biochemical environment found within a live cell. It is therefore an ideal approach for confirming putative interactions suggested by yeast two-hybrid or mass spectrometry proteomics studies, and in addition it is well-suited for mapping interacting regions, assessing the effect of post-translational modifications on protein-protein interactions, and evaluating the impact of mutations identified in patient DNA.

Interactions between proteins are fundamental to all cellular processes. Using Bioluminescence Resonance Energy Transfer, the interaction between a pair of proteins can be monitored in live cells and in real time. Furthermore, the effects of potentially pathogenic mutations can be assessed.

Untersuchung von Protein-Protein-Interaktionen in lebenden Zellen Mit Biolumineszenz-Resonanz-Energie-Transfer

Assays based on Bioluminescence Resonance Energy Transfer (BRET) provide a sensitive and reliable means to monitor protein-protein interactions in live ...

Probing High-density Functional Protein Microarrays to Detect Protein-protein Interactions

High-density functional protein microarrays containing ~4,200 recombinant yeast proteins are examined for kinase protein-protein interactions using an affinity purified yeast kinase fusion protein containing a V5-epitope tag for read-out. Purified kinase is obtained through culture of a yeast strain optimized for high copy protein production harboring a plasmid containing a Kinase-V5 fusion construct under a GAL inducible promoter. The yeast is grown in restrictive media with a neutral carbon source for 6 hr followed by induction with 2% galactose. Next, the culture is harvested and kinase is purified using standard affinity chromatographic techniques to obtain a highly purified protein kinase for use in the assay. The purified kinase is diluted with kinase buffer to an appropriate range for the assay and the protein microarrays are blocked prior to hybridization with the protein microarray. After the hybridization, the arrays are probed with monoclonal V5 antibody to identify proteins bound by the kinase-V5 protein. Finally, the arrays are scanned using a standard microarray scanner, and data is extracted for downstream informatics analysis1,2 to determine a high confidence set of protein interactions for downstream validation in vivo.

Using protein microarrays containing nearly the entire S. cerevisiae proteome is probed for rapid unbiased interrogation of thousands of protein-protein interactions in parallel. This method can be utilized for protein-small molecule, posttranslational modification, and other assays in high-throughput.

Probing hoher Dichte Funktionale Protein-Microarrays, um Protein-Protein Wechselwirkungen erkennen

High-density functional protein microarrays containing ~4,200 recombinant yeast proteins are examined for kinase protein-protein interactions using an ...

Identifying Protein-protein Interaction Sites Using Peptide Arrays

Protein-protein interactions mediate most of the processes in the living cell and control homeostasis of the organism. Impaired protein interactions may result in disease, making protein interactions important drug targets. It is thus highly important to understand these interactions at the molecular level. Protein interactions are studied using a variety of techniques ranging from cellular and biochemical assays to quantitative biophysical assays, and these may be performed either with full-length proteins, with protein domains or with peptides. Peptides serve as excellent tools to study protein interactions since peptides can be easily synthesized and allow the focusing on specific interaction sites. Peptide arrays enable the identification of the interaction sites between two proteins as well as screening for peptides that bind the target protein for therapeutic purposes. They also allow high throughput SAR studies. For identification of binding sites, a typical peptide array usually contains partly overlapping 10-20 residues peptides derived from the full sequences of one or more partner proteins of the desired target protein. Screening the array for binding the target protein reveals the binding peptides, corresponding to the binding sites in the partner proteins, in an easy and fast method using only small amount of protein.
In this article we describe a protocol for screening peptide arrays for mapping the interaction sites between a target protein and its partners. The peptide array is designed based on the sequences of the partner proteins taking into account their secondary structures. The arrays used in this protocol were Celluspots arrays prepared by INTAVIS Bioanalytical Instruments. The array is blocked to prevent unspecific binding and then incubated with the studied protein. Detection using an antibody reveals the binding peptides corresponding to the specific interaction sites between the proteins.

Peptide array screening is a high throughput assay for identifying protein-protein interaction sites. This allows mapping multiple interactions of a target protein and can serve as a method for identifying sites for inhibitors that target a protein. Here we describe a protocol for screening and analyzing peptide arrays.

Ermittlung von Protein-Protein-Interaktionsstellen unter Verwendung von Peptid-Arrays

Protein-protein interactions mediate most of the processes in the living cell and control homeostasis of the organism. Impaired protein interactions may ...